I think it was Dysan that first showed up with
reinforcing ring kits to
be applied to disks to ameliorate the problem, but ultimately the
solution turned out to be making sure that the motor was on during the
seating process. That's why, for example, 5.25" DD media usually has
hub reinforcement, but HD media rarely does. By the time HD media was
a
thing, the problem had been solved.
Chuck,
Then why was is it that DD media bought well after HD media was available, in use, and the
norm still had the reinforced ring? Tradition?
-Ali